1. Field of Invention
Embodiments of the subject matter disclosed herein generally relate to methods and systems and, more particularly, to mechanisms and techniques for distributing a particle separation device and a flow regulation device for handling a cooling flow in a turbo-machinery.
2. Description of the Prior Art
During the past years, with the increase on the price of fossil fuels, the interest in developing subsea compressors used in sub-sea extraction of the fossil fuel has dramatically increased. As shown in FIG. 1, a sub-sea oil/gas extraction system 10 is partially disposed on the seabed 12, closed to a well 14 from which oil is extracted. The system may include various components 16 (for example, a blowout preventer and other known equipment for maintaining the pressure and the integrity of the well in case of sudden changes in pressure) and a compressor 18 that may be used to pump to the surface 20 the oil/gas extracted from the well 14 such that the oil/gas is collected at a vessel 22 that may float above the well 14. The oil/gas is pumped from the compressor 18 to the vessel 22 through a riser 24. For generating the required pressure for pumping the oil/gas to the surface 20, the compressor 18 is driven by a motor 26, which is directly connected to the compressor 18 via a link 28. However, the bearings supporting the shaft (not shown) of the compressor 18, due to the high rotational speed of the rotor, may develop a significant amount of heat that needs to be removed for a proper operation of the compressor 18. Also, the motor 26 needs to be cooled, as the heat building up in the motor 26 may be significant during operation.
For this reason, compressor 18 may divert a portion of the fluid being compressed (for example, gas from an outlet of the compressor) to cool the bearings of the compressor 18 and parts of the motor 26. The diverted fluid may be split between the compressor 18 and the motor 26 and the part of the diverted fluid flow that is used to cool down the motor 26 may be supplied by a dedicated pipe 30 from the compressor 18 to the motor 26 as shown in FIG. 1.
However, the diverted fluid may include dirt or foreign particles (impurities) that are undesirable inside the compressor 18 and/or motor 26, especially inside their bearings. For this reason, filters or dust removing devices may be used to clean the diverted fluid prior to cooling the bearings of the compressor 18 and/or the motor 26. Such devices for removing dust and/or particles are disclosed, for example, in U.S. Pat. No. 7,311,741 to Anderson et al., and U.S. Pat. No. 3,907,671 to Baigas, Jr, the entire contents of which are enclosed here by reference.
The system 10 shown in FIG. 1 may include a flow regulation device (not shown) that controls a volume of the fluid supplied to the bearings of the compressor 18 and to the motor 26. Depending on the various conditions under which system 10 is used, this diverted volume of fluid (either to the compressor 18 or to the motor 26) changes from time to time. The flow regulation device is traditionally separated from the dust removing devices as the dust removing devices are placed outside the compressor 18. Further, the traditional flow regulation device is provided deep inside a casing of the compressor 18, a position which is difficult to be accessed from outside.
Thus, in order to modify the flow regulation device in the eventuality of a change in operation of the compressor, the whole compressor 18 has to be disconnected from the seabed 12, brought up to the surface at a dry facility, and then the compressor 18 has to be disassembled such that the flow regulation device can be reached and replaced with another appropriate flow regulation device. Alternatively, the same flow regulation device is maintained, but various removable ring elements having different orifices are provided inside the flow regulation device to alter the flow of the fluid. Once the compressor 18 is disassembled at the dry facility, it takes between half a day and three days for reaching and removing the flow regulation device of the compressor, because of the multiple connections of the flow regulation device to the casing of the compressor and the dust removing device inside or outside the compressor. Thus, maintenance personnel need to reach inside the compressor and detach the flow regulation device from the casing of the compressor and from the particle separation device in order to change it.
This time consuming operation results in the temporary suspension of operations of the oil extraction system 10, which implies loss of production. Thus, it is undesirable to shut down the entire operation of system 10 for two or three days for modifying the flow regulation device depending on the operating conditions of system 10.
Accordingly, it would be desirable to provide systems and methods that avoid the afore-described problems and drawbacks.